^Heman-Achah, Yolanda. [www.phillyent.com/pdf/physiologyofvoiceproduction.pdf "Physiology of Voice Production: Considerations for the Vocal Performer"] (PDF). Retrieved 31 March 2012. {{cite web}}: Check |url= value (help)
^Fenske, Jill D. (May 1999). "Human breath emissions of VOCs". Journal of the Air & Waste Management Association. 49 (5): 594–598. doi:10.1080/10473289.1999.10463831. PMID10352577. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: date and year (link)
^Martonen, Ted B. (2002). "Flow Stimulation in the Human Upper Respiratory". Cell Biochemistry and Biophysics. 37 (1): 27–36. doi:10.1385/CBB:37:1:27. PMID12398415. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
^Kenyon, C.M. (1997). [jap.physiology.org "Rib cage mechanics during quiet breathing and exercise in humans"]. The American Physiological Society. 83 (4): 1242–1255. Retrieved 03/28/2012. {{cite journal}}: Check |url= value (help); Check date values in: |accessdate= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
^Tamimi, Asad (March 2012). "The Effects of Cigarette Smoke on Airway Inflammation in Asthma and COPD: Therapeutic Implications". Respiratory Medicine. 106 (3): 319–328. doi:10.1016/j.rmed.2011.11.003. PMID22196881. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: date and year (link)